Background: Low-intensity shock wave therapy (LiST) improves erectile function in patients with erectile dysfunction (ED), probably by promoting angiogenesis as suggested by studies on animals with comorbidities as disease associated ED models.
Aim: To investigate the effects of LiST on erectile tissue of healthy, naturally aged rats.
Methods: Twelve aged male Wistar albino rats (19-21 months) were randomized into two groups: a control group (OC, n=6) and a LiST treatment group (OSWT, n=6).
Another young control group (8 weeks) (n=6) was also used (YC). Each rat in OSWT group received 300 shockwaves with an energy flux density of 0.09mJ/mm2 at 2 Hz.
Sessions were repeated three times/week for two weeks, followed by a two week washout period. Penile tissues were harvested and analysed with real time reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemical analysis (IHC).
Main Outcome Measures: Expressions of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS), nerve growth factor (NGF) and neuronal NOS (nNOS), as well as a1 and a2-adrenergic receptors (a1AR, a2AR).
Further IHC for the significant mRNA expressions was performed.
Results: The expression of VEGF, eNOS and a2AR/a1AR ratio were increased (ANOVA: p=0.039, p=0.048 and p=0.008 respectively). The expression of NGF was not affected, but an increase in nNOS was observed (p=0.093). The increase of VEGF, eNOS as well as a2AR was also observed in IHC.
Clinical Translation: LiST showed to reverse pathology associated with aging in the erectile tissue in rats, which supports future research for ED prevention.
Conclusion: VEGF and eNOS expressions seem to play key role in the mechanism of action of LiST, apparently by inducing angiogenesis. For the first time a positive modulation of sympathetic nerve system as expressed by increased a2AR/a1AR ratio was also observed.
shockwave therapy, erectile tissue, erectile dysfunction, ESWT, LiST, aged rat